Locard's Theory
by mayhit
Summary: It's touch is very gentle. It leaves no prints.
1. Chapter 1

_Name: Locard's theory._

_Disclaimer: Not mine._

_Rating: PG-13 maybe?_

_Description: Grissom, Sara and the confusion of influence._

_From the story: "Its touch is very gentle, it leaves no prints."_

_Author's notes: Whatever. Um, check out song lyrics for "Long December" by "The Counting Crows" and "Volcanoes" by "Damien Rice"._

_------------------------------------------_

Sound:

A lecture hall built for 115 students. Of the 204 that show up only 168 are on time. Only 103 bring textbooks. 74 arrive with scientific calculators, 39 bring the recommended 1 liter water bottle and 5 come fully equipped with pre made notes, though 2 of which have been scribbled directly into the margins of their, _This-Costs-More-Than-A-Months-Rent_ Entomology and Forensics text books.

A man who cannot possibly be old enough to be their teacher arrives through the public entrance doors approximately 20 seconds late and takes his place on stage. The first thing Gil Grissom ever says in front of a live audience is something about the eating habits of locusts.

"_Never mind,"_ thinks each student in turn, _"he's old enough."_

Grissom wonders what percent of one's audience must understand a joke in order for the joke to become funny. Of 204 students in various states of attendance, exactly four react to his.

He determines,_ "More than 1.9 percent."_

Two minutes later she stumbles in- the sight of her before the sound has reached him and, _"This,"_ he thinks, _"is the first time I've ever noticed the difference between the speed of light and sound."_

She is hectic and empty handed and he is talking about the gestation of mosquito larvae. He wants to tell her she's too late- thinks maybe he will but then-

"Oh, this is the Burnidel case! Didn't you solve that by identifying traces of Red Brush Algae on the perpetrator's clothes?"

By the time she has made her way to the front of the center aisle she has stumbled twice and he can't take his eyes off her.

And so it is that after four hours in a lecture hall, 203 half suffocated science majors press slowly from the back doors while one student remains behind, attempting to read the notes she has scrawled in messy faux abbreviations upon her arms. _"This isn't anything,"_ thinks Grissom and when she makes her way towards the stage he watches her, feeling magnetized. At once attracted and repelled depending on the angle he approaches this.

"You've been studying." He deduces.

"If that's what you call it."

He glances up from his illegible lecture notes in time to witness her touch her face, entranced-

"What do you call it Miss Sidle?" -and touching only her lips now, this careful contemplation on her face but when she pulls her hand away, about to answer, she sees his expression and knows instantly, "Oh god! The _ink_!"

In a study hall in San Francisco Grissom watches a twenty three year old with scribble from fingernails to elbows slowly smudge a trace of blue along her bottom lip- he doesn't know what to think.

She rubs at the stain with her cotton sleeve and leaves handprints on her shirt, lip marks along the cuff like hypothermic kisses. "Okay, I'm glad it's from a thrift store," she says, but under her breath- "_shit_."

He supposes it was only such a small amount of blue that brought the concept to his mind- that curious idea of touch made visible. He supposes it maybe wasn't even important in the end and perhaps he would have loved her anyways, she was just a virus- _can't be cured_. But she looks up at him with her lip to her white shirt- her eyebrows knit in determination and what he doesn't say is, _"It's been nice meeting you."_

"_I have a flight in the morning."_

"_Good luck in your profession."_

"_Goodbye."_

"Are you familiar with Locard's theory?" he chooses instead, because of course she is and of course she's delighted to hear the name of such an old friend.

"He believed that whatever event occurs-" but she cuts him off eagerly- "We leave traces."

"_And_ we bring traces with us when we leave."

"So, what are you going to bring from this event, Grissom?"

The fact that she's left off the prefix should really disturb him but all he can think to say is, "I've been looking for a- a strong cup of coffee."

It's so easy. Neither has been sleeping lately.

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Taste:

_Later, he has syrup on his palm when he associates her with pancakes. "Something new," he says…_

A hairless man with a gun. Catharine on the stairs and Grissom beneath the flickering hundred-watt bulb, heart in his throat for the first time since he can remember.

"_Well, no-"_ he thinks, _"There was Nick with that cold case."_ A broken fish tank and another moment made memorable by the presence of a gun.

So maybe it's the feeling of community created by the presence of another gun. Four pounds of metal and he could be dying in emergency, dead in emergency, dead in a basement with a murder's hands covered in what is left of a person.

It's a bit of a shock to Catharine when he nods his head in agreement and says, "Okay. Pancakes." But no one argues. Maybe it takes facing death for Grissom to allow simplicity to creep in.

And they go, just sit and let the yellow Formica-sparkled light illuminate the morning. They order all kinds of things that no one's ever even though about ordering before- "Carpe Diem" and all of that.

Apparently seizing the day extends as far as chocolate chips and whipped cream and sprinkles on the whipped cream, banana flavored batter (Warrick) and coffee flavored syrup (Sara). Nick is sure to let Sara know that the preservatives in sprinkles cause hair breakage and Sara calmly lets Nick know, "guess where you can put that lovely factoid?" –and life is something transcendent, yes-

But Grissom sits quietly, feeling his pulse in his chest:

"_Well no, there was Holly Gribbs,"_ and, _"Gil, she's dead,"_ and, _"Oh God, this used to feel like dying but now it's only…"_

He is adrenaline buzzed and stutter shook- not thinking accept that she's almost touching him beneath the table and he wants to prove it- wants to define something- maybe anything or maybe just _this_ thing. He really isn't thinking just now.

Sara caught a ride with him to Ed's Pancake World- brushed her hair into a pony tail in the 2 inch by 2 inch visor mirror and said nothing until they were pulling into the parking stall. His hand on the door handle and she was painted healthy colors in the morning sunlight so it came as a surprise to Grissom when she said, "Tonight, when you feel this, if- if you need to… well you know, if you just need to _think_ with someone…"

In Ed's with Elvis singing something about 'conversation' in the background, their orders arrive. For Grissom who is not used to eating in the proximity of others, he spends much of the first half hour listening to the low hum of the ceiling fan, remembering to eat when Catharine shoots his plate (never him) a glance every now and then. It certainly does not seem strange when Nick reaches across the table and forks a bite of Catharine's _Toffee Kahlua Cakes_. Not even such a surprise when Sara sneaks a testing of Nick's _Apple Pie A La Creme Cakes-_ her theft going unnoticed while Nick is checking out the waitress.

And so maybe it is the feeling of community created by the presence of that gun, but when Sara gasps a laugh- just so slightly too harsh- and he can smell the bitter sweet of coffee syrup on her voice, it's Grissom who knows she's been holding her breath…

"_Well no, there was us outside the Monaco."_ and, _"Wouldn't you if you were married to Mrs. Roper?"_ and, _"Oh God, this really isn't anything. This didn't used to feel like-"_

It barely even seems a surprise when he reaches across the table and takes a careful slice from the corner of her pancake- places it in his mouth.

"_This doesn't have to mean-"_ he's thinking and the others apparently agree. They skip right over the moment, discussing Nick's new car. "Honestly, it came with three traffic tickets," Nick says and Sara's leg is an inch from his own beneath the table_. "Sharing the fourth sense,"_ thinks Grissom, _"should not be permitted in a public location."_

When he carefully sets down his fork, he has syrup on his palm and he's not sure he'll ever think of her again without the taste of sticky pancakes. "Something different," he says very lightly to her confused expression, but Oh God, this didn't used to taste like anything.

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While the busker plays _Three Marlenas:_

From the empty auditorium, with only the smell of fresh sweat and stale chalk, they find a coffee shop and, "I think anything would be a welcome alternative to the campus," Sara says.

She's been spending eighteen hours a day in various work-ethic promoting buildings. He inquires as to her activities and she surprises him by saying, "Exams."

He should really try to remember; she's only twenty-three. But then he steals himself and tells her the joke about the locusts- stupid as it is. He thinks he might even get the wording a little wrong but he tells himself: it's for a study. He needs to know.

Of the two, both are ultimately true, but only one in the way he means immediately.

She laughs when she discovers the punch line, ducking into her cup to smother the sound and no, no, no, he really shouldn't be here.

He swallows his coffee fast enough to burn his tongue- diversion is as efficient as morphine if you do it properly- and he's hoping to divert the manic intensity of her creeping through him like coffee one hundred proof.

He thinks he needs to revise his hypothesis. It's not about the percentage of people who laugh at a joke but the identity of those who do. He'll never tell this one again.

A girl with, _"cockroach cochlea?"_ scrawled across her knuckles like some secret language he could lick from her skin and when she laughs he has no aspirations left for it.

Their chatter is quiet and their words are often embarrassingly long but her caffeinated meanings come as bruising conclusions.

She is blindingly premeditated and, "Sara Sidle," he thinks, "must be what is meant by 'a quick study'".

He'll feel this tomorrow.

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Smell:

A Decomposing body and Grissom standing in the hall- without disgust, without judgment.

"Lemon's" he recommends before leaving her there, looking in through the soundproof window at David. David could love her- maybe does. For a moment she thinks…

But that would be a lie of the worst variety and she knows it.

Seven hours later she has her hands in human soup when nick comes in- that sound in his voice like he can't figure out how to use his nose. She names the body; tries to feel something, anything that might be what _He_ would feel…

She feels only soup.

Realizing this, she is driven to frustrated convulsions and, of the three options provided she chooses dry heaving over the other, saltier alternative. Never mind laughter, she's too out of practice.

That afternoon is when Hank, she will later believe, made the decision to stay with his girlfriend. She finds it almost tolerable because he did not decide _not_ to be with her. Of course, emotion is never such a simple thing. People have invisible values and, like some game show, the values are unknown until the moment they become thought.

"_Perhaps-"_ she thinks later, gasping into the shower nozzle, breathing in the smell of hand squeezed lemons, _"-that is what David has that we do not. Nothing but patient emotion for the Victims."_

David could really love her, shower her down with the taste of clean hot steam; wash everything worthless and heavy, so gently down the drain until all that was left of her was shiny silver things- rings and brilliant teeth. She thinks for a moment that maybe she could care for him, kiss him in the break room at 7 PM and amidst the DB's on her midnight lunch hour. A lie of the worst kind- half truth- but isn't that really what she finds so tempting?

Grissom is all thought. She has felt it in his hands, touched the things he has, like the way seashells remember the ocean- the intelligence of his hands is imprinted forever.

In the shower, gripping lemons like painful secrets, Sara comes to understand that she is as much a vessel for these imprints as any other instrument he could possess. She turns the cold water nearly off and scalded- frustrated in _every_ sense of the word- she considers the possibility that there may be a fourth kind of convulsion she has not yet explored…

Tomorrow David will look at her as though he knows- smile shyly without disgust, without judgment-

She will excuse herself and breath into the fountain in the hall for a moment before returning. In the end David sees the desperation- not in her eyes but in the way she moves, so careful with the hips- and says only, "You smell like lemon's."

She buys five pounds of the bitter fruit from a family grocery store she has never been in before. _Francine's_ is on the way to her house and she needs the convenience. She can't excuse anything if her actions lack convenience. She pays at the counter (twice the price) and drops two pennies with numb hands, forcing the change angrily into her pocket. She knows he will notice eventually- distances herself from the idea that he'll feel anything at all. He will never say a word.

That's okay; it's only for her anyway. There is a connection she cannot put into words, but scent, she knows, is the strongest sense tied to memory and she believes it started there.


	2. Chapter 2

While the busker plays _Volcanoes:_

Two hours in their chairs, three cups of black _Christmas Blend_ and she's getting jitters- turns them into shivers when she tries to hide them from him. He wants to touch her to feel the small vibrations. It could be innocent, he could make this innocent, he could just-

_Contact._

He turns her hands over, chooses the one with _"Grasshopper DNA?"_ careening along the thumb and wonders, "Why are they all questions?" He knows the answer but wants to hear it from her.

"I guess because knowledge isn't really _achieved_," she considers and with her hand still in his, her voice cracks like November-brittle birch trees when she commits: "Ever."

So it is to defuse the moment that he inquires: "Why didn't you bring any paper?" -such a simple question, he never would have guessed where this would lead…

And maybe it's the distraction he is providing, pushing his thumbs into her blue smudged palms (though that's really not where she's feeling him) but somehow she's saying, "You like my arms? You should see my legs." And because he wants to, it really is over now. He has a flight in the morning. Good luck with her profession. Goodbye.

Fifty seconds into the Air Line Attendant's safety protocol it occurs to him that he never got an answer. A girl with nothing but a _Bic_ pen shoved into her messy ponytail comes dashing into a lecture hall. Why in the world didn't she bring paper?

He finds himself believing that this one missing piece could break the case. Clever of her not to answer; he never could resist a puzzle.

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Touch:

_The word "No" is too heavy to support it's own weight. Grissom has read books about insects- their exoskeleton's too thin for their mass and they die of suffocation. In language however, many sentiments can be carried by their recipients. What a devastating testament of human nature that the most hurtful of the language's creations are often held onto the longest._

_The damaged brunette in his doorway would never admit: _

_she carries every word she's ever heard him speak…_

An explosion in the lab. Greg Sanders on a stretcher and far too many blaring lights. Grissom can smell it- the chemical responsible for this. He could name it if his ears weren't ringing. Then he sees her and for 90 seconds, he forgets what he is supposed to be doing.

She's sitting on the curb, knees up like some small child and he's thinking, _"You've been blown apart before."_

Amidst the red and blue lights, her face is DB white, wide eyed- she is reminiscent of a family member standing stark still and, _"how could this have happened?"_

He's seen so many of these. They both have.

"Sara, are you okay?"

When she sees him coming she sits up straighter, looking at Grissom and trying to focus before she even grasps what it is she's seeing- not that she isn't used to this routine with him.

"Yeah. I'm fine."

"_Don't be so strong for me,"_ he wants to tell her, _"I won't know what to do with you."_ But instead he takes her hands in his, palms up and selects the one with a deep gash, almost down to the Pisiform, Scaphoid, Trapizoid.

This is Sara though, and he can't impersonalise with technical names; they both remember the last time they were here.

"_Its touch is very gentle, it leaves no prints."_

Grissom believes, then, without question, that if she could recall proper syntax she would wonder, "Why now? Why would you ever think that you could do this now?" and what she would mean would be, _"Stop fucking with the evidence, you'll ruin it."_

When she finds him later, she- whip lashed and believing she is indestructible- he's already decided; he has the words picked out…

Or rather, word.

19 hours until she approaches him again. Catharine is in a room with the sound of a heart monitor, crying into blankets that smell like Greg Sanders and medicine. Sara is in his office.

Now is the time to make amends.

She's standing in his doorway, mouth set in a line. If he asked her he bet she'd say it was the easiest shape to maintain (-it's not, the circle and the pyramid will top it) –but that isn't what she's interested in anyways.

"Have dinner with me."

He knew these words were coming, like handing an eight-year-old a gun with a bullet spun in the chamber and saying, _"Have you ever played this game?"_ -the only question that remains to be answered? Of the two of them, who holds the gun and who has simply supplied it?

He could damage her now, with the wrong answer but does anyone ever know which one that is?

"No." he rejects her offer- decides this must the cruelest word he knows- and now she's flat backed against his door frame saying, "Lets see where this goes-"

She doesn't understand: if she's invincible he must be fragile- there is a balance to these things. That's really what Locard meant: exchange.

It isn't until she has left his doorway vacant that he considers…

A law is _nearly_ always right but maybe this was an exception. If there is a force to bend probability, it has always been Sara Sidle- her body painted full of smudged reminders.

Tonight- Sunday, and the only night he gets- is not a 'Roller Coaster Night'. Instead he will get drunk on scotch and read _"The Sun Also Rises"_ from cover to cover. When he wakes up at 6 AM on the living room floor, and after forcing a novel's worth of words into his mind it will be the first thing he thinks: _I could have taken Charlotte's advice._

_------------------------------------------_

Sound:

A faux Starbucks squeezed between a bookstore and, ironically, the thrift store where she bought her ruined shirt. A man playing covers of everybody else's songs sits outside the window and Sara swears the glass rattles when he plays the C.

"Poser coffee tastes better," she says as though its some explanation in it's self. Grissom waits a moment and reasons that it may be, if he treats it like one of his cases.

_Don't try to analyze yet, just look. _

"It must be sad-" she considers so that Grissom can't tell if it's for the first time or the fiftieth, "-never owning anything of your own."

"It is." He says and in the end, it's the eloquence of his cynicism that undoes her.

After two hours, the lyrics to a song they've both heard before by someone better, come rasping towards them through the windowpane, half degraded and beautiful still. _A long December and there's reason to believe…_

She turns to him and this time he's certain it's a brand new contemplation when she pulls her words together before his eyes. "I think sometimes there are so many reason's to believe, that when something falls apart it's only because no one knew which reason to choose." He doesn't want to be her 'no one'. He's very sorry it has worked out this way.

It is a Long December and Grissom is thinking, _"-if you might come to California…" _

The sun has set, white gold, refracting light, but he's still appreciating the bridge of her nose- the single loose lash that has yet to fall from her smudged mascara eye. And _"Oh God,"_ thinks Grissom- he shouldn't like it here.

So finally, once she finishes her third cup of coffee and her hand shakes alarmingly when she places it down, (though perhaps that isn't entirely from the caffeine) he enquires: "Sara… If Locard's theory turns out to be correct, what are you hoping to take away from this?"

He sees his error before he's finished his question but it is too late now and she is already on him with, that sharp mind pulling at any seams it can find. "I don't think it works that way. I don't think you always want what you get."

"I think we do," presses Grissom, curling a napkin around the edge of the table, "but do we always want what we should?"

She blinks, once, twice and instead of an answer, they lock eyes across their circular table- just a circumference of 7.85 feet between them both and when that loose eyelash drifts, soundlessly to Sara's cheek, Grissom knows for the first time, that art galleries have become obsolete.

"Well then what do you believe you will take away?" he plunges ahead. "Regardless of your original intention? What now?"

She sits quietly across from him, one song ending- the beginning chords of some other, like salt in a deep cut, but Grissom believes for a moment that clumsy notes may be all that's holding the moment together. He is certain neither of them could possibly be doing it.

He wants to write this fragile lyric- nervous cursive on her wrist where the blood is humming. He thinks nobody brilliant has even known how to follow instructions. He knows he sometimes idiotically breaks his own.

In a moment they will both be stumbling over _goodbye, goodbye, goodbye._

He finds it is the mundanity of the idea that hurts: when he returns to his hotel room he will brush his teeth and not be able to remember the exact color of her mouth.

Always the smallest things and, _"so this is what tragedy feels like."_

_Don't build your world around, Volcanoes melt you down…_

Grissom (accidentally) bites his tongue, spits blood into the bathroom sink with the coolness of mint- hoping, by chance, to find what he is looking for. The color is mercury dark and nothing like her lips.

"_What are you going to take from this?" _he asks back at the coffee shop posing, so unconvincingly as a _Starbucks_. He's just trying to keep the desperation out of his voice when he realizes that perhaps the question is more towards them both than her alone. 

"45 ounces of _Christmas Blend_," Sara says at last and he knows before she does- what she means is, _"It doesn't have a name right now."_


End file.
